Builders for synthetic detergents



3,463,734 BUILDERS FOR SYNTHETIC DETERGENTS Richard P. Carter, Jr., Chesterfield, and Riyad R. Irani, St. Louis, Mo., assignors to Monsanto Company, St. Louis, Mo., a corporation of Delaware No Drawing. Filed June 16, 1966, Ser. No. 557,884 Int. Cl. Clld 1/10, N04 US. Cl. 252-99 Claims ABSTRACT OF THE DISCLOSURE Washing compositions comprising (1) surface active compounds, (2) water soluble salts of poly(itaconic acid) as builders and (3) supplemental builders are effective as detergents in an aqueous solution.

This invention relates to builders for synthetic detergents and, more particularly, to the use of the water soluble salts of poly(itaconic acid) as builders for synthetic organic anionic, nonionic and/or amphoteric surface active compounds which are suitable as detergents in aqueous solutions.

The use of builders in detergent compositions is well known today with one class in particular, the polyphosphates, being used extensively. Builders, of course, are used to improve detergency levels of the detergent compositions and due to the complex nature of detergency, that is, the various and numerous factors which are involved, there has been no general basis found With respect to either the physical properties or chemical structure of compounds from which the behavior of a detergent builder could be predicted. In general, detergent builders are believed to affect to various degrees such factors in the detergency system as stabilization of solid soil suspensions, emulsification of soil particles, the surface activity of the aqueous detergent solution, solubilization of water-insoluble materials, foaming or suds producing characteristics of the washing solutions, peptization of soil agglomerates, neutralization of acid soil and sequestration of metallic ions such as mineral hardness constituents which are often present in the washing solution. As can be appreciated from the foregoing, only a few compounds have been found which can be classed as effective detergent builders.

The mere fact that a compound is found to be an effective detergent builder, however, does not necessarily render its use advantageous in detergent compositions. The detergent builder among other things, should be compatible with the various additives conventionally found in detergent compositions, be hydrolytically stable since such compositions are often used in hot, alkaline aqueous solutions, be compatible with various bleaching agents of the oxygen and chlorine type and should not to any appreciable degree corrode or otherwise affect the metal parts of the machine or equipment in which the washing process is being conducted. To one degree or another the known builder materials, either of the inorganic or organic type, have certain limitations and disadvantages such as those previously mentioned and thus improved builders are continually sought which would obviate or minimize the limitations and disadvantages of the prior art builder materials.

Therefore, it is an object of this invention to provide an improved builder for synthetic organic surface active compounds.

3,463,734 Patented Aug. 26, 1969 Another object of this invention is to provide an improved builder for synthetic organic anionic, nonionic and/or amphoteric surface active compounds which are suitable for use as detergents in aqueous solutions.

Another object of this invention is to provide an improved washing oomposition of a synthetic organic anionic, nonionic and/or amphoteric surface active compound and an improved builder.

A still further object of this invention is to provide an improved liquid washing concentrate composition of a synthetic .organic anionic, nonionic and/or amphoteric surface active compound and an improved builder.

Other objects will become apparent from the following detailed description.

The detergent builders of the present invention are the water soluble salts of poly(itaconic acid) (solubility in water at 25 C. of at least 0.5%) and especially the alkaline salts (salts which exhibit a pH of from about 8 to about 11 in water at a concentration of 1% and 25 C.), and, in particular, the sodium salts although other alkali metal salts, such as potassium, lithium and the like, as well as mixtures of the alkali metal salts, may be substituted therefor. In addition, any other water soluble salt, such as the ammonium salt and the amine salts, which exhibit the characteristics of the alkali metal salts which may be used to practice the invention. In particular, amine salts prepared from low molecular weight amines, i.e., having a molecular weight below about 300, and more particularly the alkyl amines, alkylene amines and alkanol amines containing not more than 2 amine groups, such as, ethylamine, diethylamine, propylamine, propylenediamine, hexylamine, 2-ethyl hexylamine, N-butylethanolamine, triethanolamine and the like, are the preferred amine salts. In view of the foregoing, it is preferred that the pH of the detergent composition be such as to result in an aqueous washing solution having at least a pH of 8 (preferably about 9 to about 12) when the detergent composition is used in amounts to give effective cleansing action.

The water soluble salts of poly(itaconic acid) can be prepared by many and various methods which include those disclosed and described in US. Patent 3,055,873, issued Sept. 25, 1962, which is incorporated herein by reference.

The builders of the present invention are not only efiective detergent builders but also exhibit many and various advantageous properties which include being hydrolytically stable, that is, resistant to decomposition or degradation under high temperature and/or pH conditions, relatively inert or noncorrosive to metal parts, such as zinc, copper, aluminum and the like often found in washing equipment or machines, and stable toward bleaching agents such as oxygen and/or chlorine bleaches as well as not materially interfering with the functioning of such agents.

As previously mentioned, the builders may be used with any of the conventional detergents classed as synthetic non-soap anionic, nonionic and/or amphoteric surface active compounds which are suitable' as cleansing agents. Anionic surface active compounds can be broadly described as compounds which contain hydrophilic or lyophilic group. These compounds include sulfated or sulfoin an aqueous medium to give anions containing the lyophilic group. These compounds include sulfated or sulfonated alkyl, aryl and alkyl aryl hydrocarbons and alkali metal salts thereof, for example, sodium salts of long chain alkyl sulfates, sodium salts of alkyl naphthalene sulfonic acids, sodium salts of sulfonates abietenes, sodium salts of alkyl benzene sulfonic acids particularly those in which the alkyl group contains from 8-24 carbon atoms; sodium salts of sulfonated mineral oils and sodium salts of sulfosuccinic acid esters such as sodium dioctyl sulfosuccinate.

Advantageous anionic surfactants include the higher alkyl aryl sulfonic acids and their alkali metal and alkaline earth metal salts such as for example sodium dodecyl benzene sulfonate, sodium tridecyl sulfonate, magnesium dodecyl benzene sulfonate, potassium tetradecyl benzene sulfonate, ammonium dodecyl toluene sulfonate, lithium pcntadecyl benzene sulfonate, sodium dioctyl benzene sulfonate, disodium dodecyl benzene disulfonate, disodium di-isopropyl naphthalene disulfonate and the like as well as the alkali metal salts of fatty alcohol esters of sulfuric and sulfonic acids, the alkali metal salts of alkyl aryl (sulfothioic acid) ethers and the alkyl thiosulfuric acid, etc. Preferred anionic organic surface active agents are, as noted hereinbefore, sodium salts of alkyl benzene sulfonic acids and particularly preferred sodium salts of alkyl benzene sulfonic acids are those in which the alkyl group or radical contains to 18 carbon atoms in a straight (i.e., unbranched) chain.

Nonionic surface active compounds can be broadly described as compounds which do not ionize but usually acquire hydrophilic characteristics from an oxygenated side chain, such as polyoxyethylene, while the lyophilic part of the molecule may come from fatty acids, phenols, alcohols, amides or amines. Examples of nonionic surfactants include products formed by condensing one or more alkylene oxides of 2 to 4 carbon atoms, such as ethylene oxide or propylene oxide, preferably ethylene oxide alone or with other alkylene oxides, with a relatively hydrophobic compound such as a fatty alcohol, fatty acid, sterol, a fatty glyceride, a fatty amine, an aryl amine, a fatty mercaptan, tall oil, etc. Nonionic surface active agents also include those products produced by condensing one or more relatively lower alkyl alcohol amines (such as methanolamine, ethanolamine, propanolamine, etc.) with a fatty acid such as lauric acid, cetyl acid, tall oil fatty acid, abietic acid, etc. to produce the correspond ing amine.

Still other nonionic surface active compounds include the amine oxides and phosphine oxides and preferably the unsymmetrical trialkyl amine oxides and phosphine oxides wherein two of the alkyl groups are lower alkyl groups (1 to 4 carbon atoms) and the other alkyl group is a higher alkyl group (8 to 18 carbon atoms). Examples include dimethyldodecylamine oxide, dimethyl dodecylphosphine oxide, dimethyl tetradecyl amine oxide, dimethyltetradecyl phosphine oxide, diethylhexadecylamine oxide, diethylhexadecylphosphine oxide and the like.

Particularly advantageous nonionic surface active agents are condensation products of a hydrophobic compound having at least 1 active hydrogen atom and a lower alkylene oxide (for example the condensation product of an aliphatic alcohol containing from about 8 to about 18 carbon atoms) and from about 3 to about 30 mols of ethylene oxide per mol of the alcohol, or the condensation product of an alkyl phenol containing from about 8 to about 18 carbon atoms in the alkyl group and from about 3 to about 30 mols of ethylene oxide per mol of alkyl phenol. Other advantageous nonionic detergents include condensation products of ethylene oxide with a hydrophobic compound formed by condensing propylene oxide with propylene glycol.

Amphoteric surface active compounds can be broadly described as compounds which have both anionic and cationic groups in the same molecule. Such compounds may be grouped into classes corresponding to the nature of the anionic-forming group, which is usually carboxy, sulfoor sulfato. Examples of such compounds include sodium N-coco beta amino propionate, sodium N-tallow beta amino dipropionate, sodium N-lauryl beta iminodipropionate and the like.

Other typical examples of these catagories of the anionic, nonionic and/or amphoteric surface active' agents are described in Schwartz and Perry Surface Active Agents Interscience Publishers, New York (1949) and the Journal of American Oil Chemists Society, volume 34, No. 4, pages 170-216 (April 1957) which are incorporated herein by reference.

The amount of builder necessary to be used with the surface active compound (active) may vary depending upon, inter alia, the end use, type of active employed, pH conditions and the like. In general, the builders of the present invention can be employed in detergent compositions in any desired proportions which are effective, that is, which enhance the detergency characteristics of the surface active compound (active). The optimum active/ builder ratio depends upon the particular active employed and the end use for which the detergent composition is intended but will fall within the range of an active/ builder weight ratio of about 4:1 to 1:4.

Often the builders of the present invention can be employed advantageously in conjunction with other detergent builders (supplementary builders) which include the conventional alkali metal polyphosphates, i.e., the tripolyphosphates and pyrophosphates, (sodium tripolyphosphate, tetrasodium pyrophosphate, tetrapotassium phosphate, disodium pyrophosphate and the like) the amino polycarboxylic acids and salts such as the sodium, potassium and ammonium salts of nitrilotriacetic acid (trisodium nitrilotriacetate), the sodium, potassium and ammonium salts of amino tri(methylenephosphonic acid), as well as the free acid, and the diphosphonic acids and salts (methylene diphosphonic acid and l-hydroxy, ethylidene diphosphonic acid) as disclosed and described in Canadian Patent 718,385 issued Sept. 21, 1965, which is incorporated herein by reference. Generally speaking, a weight ratio of the poly(itaconate) builder and the foregoing described builder or builder mixtures of from about 1:10 to 10:1 have been found to be particularly effective as a detergent builder composition.

As a liquid washing concentrate composition useful for virtually all washing and cleaning situations including laundering and dishwashing, the detergent compositions of the present invention (active and builder) are particularly advantageous. Such concentrate compositions are either water or water-alcohol based of either the solution or emulsion type and can contain hydrotropes such as the water soluble alkali metal salts (particularly sodium and potassium) of toluenesulfonate, benzene sulfonatc and xylenesulfonate in an amount of from 0 to about 12% by weight or a polyelectrolyte (ethylene-maleic anhydride copolymers and methyl vinyl ether-maleic anhy-- dride copolymers) as stabilizing components in an amount of from 0 to about 8% by weight. In addition, the water i or water-alcohol mixture is usually in an amount of from n' about 20% to about by weight of the concentrate. composition.

The detergent compositions of the present invention can be prepared in any of the several commercially desirable composition forms such as, bar, granular, flake, liquid and tablet forms.

The resulting detergent composition, that is, the active and builder, of the present invention is generally effective when used in aqueous systems in conventional amounts which are generally about 0.2% concentration or below.

The invention is not to be limited to any particular method of preparing the detergent compositions containing the builder and the surfactant. The builder may be mechanically mixed in, crutched in the surfactant in the form of a slurry, or dissolved in a solution of the surfactant. In addition, the builder may be admixed with the surfactant in any of the forms in which the surfactant is manufactured in, as well as being added simultaneously or separately to an aqueous solution. In any event, the builder is intended to be used with the surfactant at the time of application as a cleansing agent.

In order to illustrate the invention, a poly(itaconate) builder was compared under carefully controlled conditions with sodium tripolyphosphate for building properties in hot water. The conditions of the test were: hardmess-300 p.p.m.; total detergent concentrations-0.2%; temperature-60 C.; pH-9.5. The tests were made in a Launder-Ometer machine on standard soiled fabric specimens.

The following detergent compositions were used in the test with the percentages being by weight in the aqueous washing solution:

Percent Sodium dodecylbenzene sulfonate 0.04 Builder 1 0.05 Sodium silicate 0.02 Sodium carboxymethylcellulose 0.00065 TABLE 1 Builder: Percent soil removal (1) Sodium poly(itaconate) 29 (2) Sodium tripolyphosphate 27 (3) No builder present 5 The above results indicate that a builder of the present invention compares very favorably with sodium tripolyphosphate, a widely used builder. Therefore, it can be appreciated that the new detergent builders of this invention exhibit building properties comparable or better to conventional widely-used builders and can be used advantageously in many applications where the conventional builders are not suitable.

As previously mentioned, the builders of the present invention exhibit the highly advantageous property of being stable in the presence of chlorine bleaches (chlorine-releasing agents) without materially interfering with the functioning of these agents. The chlorine-releasing agents which are suitable for use are those water-soluble organic and inorganic compounds which are believed to have oxidizing power by virtue of containing availablechlorine which can react in aqueous solution to form hypochlorous acid or the hypochlorite ion. Such organic compounds include the alkyl hypochlorites and especially the lower alkyl hypochlorites, such as ethyl hypochlorite, propyl hypochlorite, n-butyl hypochlorite and tert-butyl hypochlorite; the N-chlorinated heterocyclic compounds and especially the five and six membered N-chlorinated heterocyclic compounds, such as, hydantoin, N-chlorosuccinimide and the triazines, such as, the cyanuric acids and salts which include trichloroisocyanuric acid, dichloroisocyanuric acid, sodium dichloroisocyanurate, and potassium dichloroisocyanurate, polychlorocyanurate' complexes as disclosed and described in United States Patents 3,035,- 054; 3,035,056; 3,035,057; 3,150,132 and 3,072,654 such as [(monotrichloro)tetra-(monopotassium dichloro) pentaisocyanurate] as well as melamine, ammeline and ammelide; and the N-chloro aromatic and substituted aromatic sulfonamides, such as, sodium benzene sulfochloroamide, sodium nitrobenzenesulfochloroamide and sodium p-toluenesulfochloroamide. Such inorganic compounds include the alkali metal chlorine containing compounds, such as, sodium hypochlorite, sodium chlorite and lithium hypochlorite, the alkaline earth metal chlorine containing compounds, such as calcium hypochlorite and barium hypochlorite, and the chlorinated trisodium phosphates, a class of compounds which consist of physico-chemical combination in unitary crystalline form of trisodium phosphate and sodium hypochlorite. The chlorinated trisodium phosphates" are known and are described along with their methods of preparation, in United States Patent 1,555,474 or 1,965,304.

1 Sodium salt of pol v(itaeonic acid) (pH-).

The term active or available chlorine is commonly used in the hypochlorite bleaching and sterilizing art to refer to atomic or nascent chlorine. Such chlorine differs from normally occurring chlorine in that the latter occurs in molecular form and each molecule contains two atoms of chlorine. When employed for bleaching purposes the active or available chlorine has twice the oxidizing or bleaching purposes the active or available chlorine has twice the oxidizing or bleaching activity of molecular chlorine based on the weight (molecular) of the normally occurring molecular chlorine. Thus, the terms active or "available chlorine are generally expressed as twice the amount in terms of percent of the chlorine present in a molecule of material.

Due to the many and varied chlorine-releasing agents which vary in molecular weight and available chlorine over a wide range and the fact that the amounts of the chlorine-releasing agent used in many applications are based on the available chlorine content, the amounts suitable for use herein unless otherwise indicated will be based on percent available chlorine per total weight of the particular composition. By knowing the molecular weight of the particular chlorine-releasing agent, its available chlorine, and the available chlorine desired expressed in percent available chlorine per total weight of the particular composition, the necessary amounts on a weight basis can be determined readily.

Although the amount of a chlorine-releasing agent in the detergent composition can vary considerably, it is preferred that an amount of from about 0.1% to about 25% available chlorine be used. Moreover, for most end use applications the usual available chlorine may vary from about 0.001% to about 0.05% available chlorine per weight of aqueous solution.

In order to illustrate the relative stability of various organic builders which are effective in the alkaline pH region, i.e., about 8-12, and a builder representative of the instant invention in aqueous solutions containing chlorine-releasing agents, the following tests and comparisons were made with the indicated results. The tests were carried out in relatively concentrated solutions containing 3% by weight of both builder and sodium hypochlorite at pH 10 and 25 C. The measurements were made of percent original available chlorine remaining after 3 hours with the hypochlorite determined iodometrically by thiosulfate titration.

The following table indicates the results of the above comparisons:

TABLE 2 Original hypochlorite Builder: remaining (percent) (1) disodium ethylene diamine tetraacetate-2H O .7 2) trisodium nitrilo Iriacetate-H O .7 (3) sodium poly(itaconate) 62.8

As can be observed from the above table the organic builders (1) and (2) would not be considered suitable in many applications for use with a chlorine-releasing agent since less than 1% original hypochlorite remained after 3 hours in the presence of the builders. However, with a builder of the instant invention, (3), more than 60% of the hypochlorite remained after 3 hours in the presence of the builder. This dramatically illustrates the unique and totally unexpected compatibility between a builder representative of the instant invention and a chlorine-releasing agent.

As previously mentioned, the builders of the present invention exhibit the highly advantageous property of being relatively inert or non-corrosive to metal parts, such as those containing zinc, copper and/or aluminum, often found in washing equipment or machines.

In order to compare the corrosive properties of organic builders such as nitrilotriacetic acid with builders of the present invention the following tests were carried out.

weight before-weight after X 100 weight-before TABLE 3 Percent Builder Metal weight loss (1) Sodium nitrilotriacetate Al 0. 87 (2) Sodium poly(itaconate) Al 0.27 (3) Sodium nitrilotriacetate. 1. 75 (4) Sodium poly(ltaeonate). 0.05

As can be observed from the above table, sodium nitrilotriacetate was quite corrosive to both aluminum and copper whereas a poly(itaconate) builder was not corrosive to any appreciable degree towards copper or aluminum under the foregoing test conditions.

While a detergent composition in accordance with this invention need contain only a detergent active of the class described and a poly(itaconate) builder it will be appreciated that the incorporation in the composition of additional ingredients commonly used with cleansing agents, such as perfume, antiredeposition agents (e.g., carboxymethylcellulose), brightening agents (e.g., fluorescent dyes) and the like, are contemplated as being within the invention.

The following detergent compositions, in which the percentages are by weight, are presented as being illustrative of the present invention:

Percent Sodium dodecylbenzene sulfonate 20 Sodium poly (itaconate) 50 Sodium carboxymethylcellulose 1 Sodium silicate Sodium sulfate 19 Nonionic condensate (dodecyl alcohol ethylene oxide a 1:10 molar ratio basis 10 Tetrapotassium pyrophosphate 10 Potassium poly (itaconate) 19 Sodium carboxymethylcellulose 1 Water 60 (III) Sodium N-coco beta amino propionate 20 Poly (itaconate) builder 50 Sodium carboxymethylcellulose 1 Sodium sulfate 29 Poly (itaconate) builder:

(1) Ammonium poly (itaconate). (2) Triethanol amine poly (itaconate).

Sodium dodecylbenzene sulfonate 20 Sodium poly (itaconate) Builder 25 Sodium carboxymethylcellulose 1 Sodium silicate 10 Sodium sulfate 19 Builder:

(1) Pentasodium amino tri (methylenephosphonate). (2) Trisodium l-hydroxy, ethylidene diphosphonate. (3) Trisodium nitrilo triacetate.

(4) 50:50 weight ratio of trisodium nitrilo triacetate and trisodium l-hydroxy, ethylidene diphosphonate.

(5) 75:25 weight ratio of sodium tripolyphosphate and trisodium nitrilo triacetate.

(6) 75:25 weight ratio of sodium tripolyphosphate and trisodium l-hydroxy, ethylidene diphosphonate..

All of the foregoing detergent compositions are effective as washing compositions for cleaning materials such as textiles, hard surfaces such as dishes and walls and the like when used in concentrations of about 0.2% in water.

For dishwashing compositions, the following additives within the range specified when incorporated with a chlorine-releasing agent give an effective formulation.

Chlorine-releasing agent: (chlorinated trisodium phosphate, trichloroisocyanuric acid, dichloroisocyanuric acid, sodium dichloroisocyanurate, potassium dichloroisocyanurate or mixtures of these) percent available chlorine per total weight of formulation 5 to 2.0 Additives: Percent by weight Poly (itaconate) lto 40 Inorganic phosphate (sodium or potassium tripolyphosphate, -pyrophosphate, -orthophospl:ate or mixtures of these) Oto 30 Inert additive (sodium or potassium -carbonates, -borates, -silicatcs, -metasilicates, -sulfates, -chlorides or mixtures of these) 40 to Organic anionic surfactant lto 10 The following dry composition (parts by weight) is especially adapted for use as a machine dishwashing compound when used in amounts to give about 15 to 25 ppm. available chlorine in the water.

Sodium dichloroisocyanurate 1.7 Sodium poly (itaconate) 20.0 Sodium dodecylbenzene sulfonate 5.0 Sodium sulfate 53.3 Sodium metasilicate 20.0

What is claimed is:

1. A washing composition consisting essentially of a synthetic organic detergent selected from the group consisting of non-soap anionic, nonionic, and amphoteric surface active compounds; a builder selected from the group consisting of water soluble alkali metal salts of poly (itaconic acid), water soluble ammonium salts of poly (itaconic acid), and water soluble amine salts of poly (itaconic acid), said amine being selected from the group consisting of alkyl amines, alkylene amines and alkanol amines containing not more than 2 amine groups and having a molecular weight below about 300, said detergent and said builder being by weight within a ratio of 1:4 to 4:1; and a supplemental builder selected from the group consisting of alkali metal polyphosphates, aminopolycarboxylates, aminotri (methylenephosphonates), diphosphonates and mixtures thereof, said poly (itaconic) builder and said supplemental builder being by weight within a ratio of 1:10 to 10:1, said composition providing in aqueous solution a pH of from about 9 to about 12.

2. A washing composition according to claim 1, wherein said water soluble salt is a sodium salt.

3. A washing composition according to claim 1, wherein said supplemental builder is sodium tripolyphosphate.

4. A composition according to claim 1, wherein said supplemental builder is sodium nitrilotriacetate.

5. A composition according to claim 1, wherein said supplemental builder is sodium l-hydroxy, ethylidene diphosphonate.

6. A washing composition according to claim 1, additionally containing a chlorine releasing agent in an amount of from 0.1% to about 25% available chlorine per weight of said composition.

7. A washing composition according to claim 1, additionally containing water in the amount of from about 20% to about 80% by weight of the composition.

8. A washing composition consisting essentially of a synthetic organic detergent selected from the group consisting of non-soap anionic, nonionic and amphoteric surface active compounds; a builder selected from the group consisting of water soluble alkali metal salts of poly (itaconic acid), water soluble ammonium salts of poly (itaconic acid) and water soluble amine salts of poly (itaconic acid), said amine being selected from the group consisting of alkyl amines, alkylene amines and alkanol amines containing not more than 2 amine groups and having a molecular weight below about 300, said detergent and said builder being by weight within the ratio of 1:4 to 4:1; and a chlorine-releasing agent in an amount of from about 0.1% to about 25% available chlorine by weight of said composition, said composition providing in aqueous solution a pH of from 9 to about 12.

9. A washing composition according to claim 8 wherein said synthetic organic detergent is a non-soap anionic surface active compound.

10. A washing composition according to claim 9 wherein said water soluble salt is a sodium salt.

References l ited UNITED STATES PATENTS 3,055,873 9/62 Hull et al. 26078.5

MAYER WEINBLATT, Primary Examiner US. Cl. X.R.

(5/59) UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION patent a,usa,73u Dated August 25, 1969 Richard P. Carter, Jr. 8 Rivad R. Irani Inventofls) It is certified that error appears in the abcve-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 8 line 2 the number "5" should read .5

SIGNED Mm SEALED Ave 251970 9 Afloat:

mm B. mum, JR. Edward MM!- Gonmisaioner of Patents Mtefliu! Officer 

